Catalysts are important components of many chemical manufacturing processes, and may be used to accelerate the rate of the reaction and/or to increase the selectivity or efficiency towards the desired product(s). Catalysts can find a wide range of utilizations in different chemical reactions. The catalytic epoxidation of olefins with oxygen is an industrially useful process for preparing compounds such as ethylene oxide and propylene oxide. Catalyst compositions, such as titanated silica catalysts, have been used to catalyze the reaction of alkenes with hydroperoxides to produce corresponding epoxides. Catalyst compositions which exhibit improved activity or peroxide conversion are commercially attractive. Providing new catalyst compositions and new methods that exhibit improvements in one or more properties and/or reaction parameters remains an important goal.